Fotoxx navigates an image collection using a thumbnail browser to choose images to view or edit. Edit functions include brightness, contrast, color, gamma, white balance, tone mapping, red eyes, sharpen, blur, noise suppression, smart erase, trim (crop), resize, rotate, add text, bend/warp, many art effects, HDR, HDF, stack, and panorama. Edit functions use movable curves and sliders. Feedback is live using the whole image. RAW files can be edited and saved with deep color. Areas or objects can be selected using freehand draw, follow edge, and tone matching. Selections can be edited in place with adjustable blending. They can also be cut and pasted into other images. Any metadata can be edited, reported, and searched (filenames, tags, dates, geotags, comments, captions, ratings, etc.). Collections (arbitrary subsets) can be defined and viewed. Batch functions are available for rename, resize/export, RAW conversion, and more.

GraphicsMagick is a robust collection of tools and libraries which support reading, writing, and manipulating an image in over 90 major formats including popular formats like DPX, DICOM, BMP, GIF, JPEG, JPEG-2000, PDF, PNG, PNM, SVG, and TIFF. A high-quality 2D renderer is included, which provides a subset of SVG capabilities. C, C++, Perl, Tcl, and Ruby are supported. Originally based on ImageMagick, GraphicsMagick focuses on performance, minimizing bugs, and providing stable APIs and ABIs. It runs on all modern variants of Unix, Windows, and Mac OS X.

GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software suitable for such tasks as photo retouching, image composition and image authoring. It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, a image format converter, etc.

GTKRawGallery is a workflow-oriented photo retouching program with the necessary tools to
quickly process camera raw images.
It brings together Dcraw,
Imagemagick,
and Exiftool.
Important features include an image browser and manager for popular formats,
a full-featured Dcraw GUI for fine-tuned raw image pre-processing,
image modification tools for 16-bit/channel post-processing,
batch conversion with single workflow applicable,
a batch processor to speed up the workflow,
fast tagging,
an advanced metadata editor with EXIF,
IPTC,
and XMP write
support,
color management,
and print support,
Facebook,
Flickr,
and Picasa Web Albums publishers,
and a Dropbox uploader.

RasterImageManipulator is a free program for image processing and fractal exploration. It has many features for customizing the appearance of fractal images. These include special filters, a palette editor, gradient palette creator, and animated palette cycling.

Evolvotron is an interactive "generative art" application to evolve images/textures/patterns through an iterative process of random mutation and user-selection driven evolution. If you like lava lamps, and never got tired of the Mandelbrot set, this could be the software for you. It's implemented using Qt, and is multithreaded.

MyPaint is a program for painting images from scratch. It supports pressure sensitive graphic tablets and comes with an easy to use brush collection. The canvas size is unlimited. Layers and blending modes are supported.

Geomajas is an extensible spatial application framework, enabling integrated GIS solutions for businesses and government. It has an integrated client-server architecture, with a high focus on server-side integration of your data (be it through GeoTools or Hibernate). This means that you apply your security and business logic on the server before anything gets sent to the client, resulting in robust applications and a real thin client.

Netpbm2Gimp automatically compiles the unmodified
source code of a Netpbm graphics program into a
GIMP plug-in. The result looks and functions like
any other GIMP plug-in, although it takes much
less effort to produce than a hand-coded GIMP plug-in.

Citra FX is a set of image filter effects for
digital photos or images. It allows anyone,
regardless of experience, to turn digital images
into unique artistic looks. Citra FX comes with
many prebuilt filters from color adjustment,
contrast, and exposure to advanced filters like
water ripple, emboss, etc. You also get instant
visual feedback on what you changed. It is well
suited for both simple and advanced digital photo
or image filtering.